The highly purified DNA Pol-alpha from rat prostate tumor (PA-3) and human neuroblastoma (IMR-32) cells appeared to be inhibited by Ricin (RCA-II), and Con-A. Loss of activity (40 to 60%) of a ...specific form of DNA polymerase from IMR-32 was observed when the cells were treated with tunicamycin Bhattacharya, P. and Basu, S. (1982) Proc. Natl. Acad. Sci., USA 79:1488-1492. Binding of ConA and RCA to human recombinant DNA polymerase-alpha showed a specific labile site in the N-terminus Hsi et al.. (1990) Nucleic Acid Res. 18:6231-6237. The catalytic polypeptide, DNA polymerase-alpha of eukaryotic origin, was isolated from developing tissues or cultured cells as a family of 180 to 120 kDa polypeptides, perhaps derived from a single primary structure. Immunoblot analysis with a monoclonal antibody (SJK-237-71) indicated that the lower molecular weight polypeptides resulted from either proteolytic cleavage of post-translational modification after specific cleavages. Present results suggest DNA polymerase-alpha from embryonic chicken brain (ECB) contains an alpha-galactose-binding subunit which may be involved in developmental regulation of the enzyme. It was shown before that the catalytic subunit of DNA polymerase-alpha reduces from 186 kDa in 11-day-old ECB to 120 kDa in 19-day-old ECB Ray, S. et al. Cell Growth and Differentiation 2:567-573 by the treatment with methyl-alpha-galactose. The low molecular weight DNA polymerase activity (120 kDa) can be reconstituted to high molecular weight (Mr = 186 kDa) with an alpha-galactose binding, 56kDa lectin-like protein. Polyclonal antibodies raised against the purified lectin were able to precipitate DNA. Pol-alpha as determined by immunostaining with the polymerase-alpha-specific monoclonal antibody SJK 132-20, suggesting this is a DNA polymerase associated-lectin (DPAL). RCA-II and GS-I-Sepharose 4B chromatographies resulted in significant purification of DNA-alpha and a complete separation of polymerase complex and primase.
The present experiment aimed to explore the interindividual variability in chemosensory abilities among the elderly population. The chemosensory abilities of 559 subjects, aged from 65 to 99 years, ...were evaluated. Various categories of the elderly, including people who were living at home either without or with assistance, and people who were living in a nursing home, were interviewed. The results revealed that 43% of the sample presented well-preserved chemosensory abilities, whereas 21% of the participants presented a moderate impairment. Of the sample, 33% presented well-preserved olfactory abilities but strong impairment in gustatory abilities and 3% were nearly anosmic but remained able to perceive the salty taste, demonstrating that gustation and olfaction were not systematically damaged simultaneously. The results showed a link between the level of dependence (free living vs. living at home with help vs. nursing home) and chemosensory abilities, independently of the age effect. These results strengthen the hypothesis that the impairment of chemosensory abilities is not only an effect of age per se; rather, it is related to events that are associated with aging. Factors that lead to increased dependence (such as poor health) also lead to an impairment in chemosensory performance.
The present experiment aimed to explore the interindividual variability in chemosensory abilities among the elderly population. The chemosensory abilities of 559 subjects, aged from 65 to 99 years, ...were evaluated. Various categories of the elderly, including people who were living at home either without or with assistance, and people who were living in a nursing home, were interviewed. The results revealed that 43% of the sample presented well-preserved chemosensory abilities, whereas 21% of the participants presented a moderate impairment. Of the sample, 33% presented well-preserved olfactory abilities but strong impairment in gustatory abilities and 3% were nearly anosmic but remained able to perceive the salty taste, demonstrating that gustation and olfaction were not systematically damaged simultaneously. The results showed a link between the level of dependence (free living vs. living at home with help vs. nursing home) and chemosensory abilities, independently of the age effect. These results strengthen the hypothesis that the impairment of chemosensory abilities is not only an effect of age per se; rather, it is related to events that are associated with aging. Factors that lead to increased dependence (such as poor health) also lead to an impairment in chemosensory performance.
